(written from a Production point of view)
He is the brother of actor and director Ron Howard, and the son of actor Rance Howard. Clint's career began at the age of one, with a role in The Andy Griffith Show, a television show that starred his brother. He has worked steadily since, with roles in a number of the films his brother directs, and roles in a number of B-movies, as well. In 1989, Howard joined other Trek alumni by acting in the cop-film Tango & Cash. His co-stars from the Trek franchise were Marc Alaimo, Roy Brocksmith, Teri Hatcher, Glenn Morshower, Michael J. Pollard, and Phil Rubenstein.
Along with Majel Barrett, Joseph Ruskin, Jack Donner and Vince Deadrick, he is one of only five actors to appear in both Star Trek: The Original Series and Star Trek: Enterprise. He, Barrett, and Ruskin also appeared in Star Trek: Deep Space Nine. He also appeared on Star Trek: Discovery and is the only performer to date who appeared in both The Original Series and Discovery.
On May 5, 2009, Howard appeared on an episode of the television show Fringe written by J.J. Abrams and Alex Kurtzman, three days before the premiere of the Abrams-directed and Kurtzman co-written film Star Trek. Howard played paranoid conspiracy theorist Emmanuel Grayson, who believed he was the son of Sarek and feared an invasion by Romulans from the future (foreshadowing the plot of the film). Grayson's apartment was #1701.
He has also recently appeared in the 2018 film Solo: A Star Wars Story from the Star Wars franchise.